Quantitative Characterization of DNA Films by X-ray photoelectron spectroscopy

Published

January 20, 2004

Author(s)

D Y. Petrovykh, H Y. Kimura-Suda, Michael J. Tarlov, L J. Whitman

Abstract

Self-assembled films of thiolated poly(dT)25 single-stranded DNA (ssDNA) on gold areintroduced as a model system for quantitative characterization of DNA films by XPS. Weevaluate the applicability of a simple substrate-overlayer model for data analysis, examine model parameters used to describe DNA films, e.g. density and electron attenuation length, and carry out a number of self-consistency checks. The model is used to obtain quantitative composition and coverage information as a function of immobilization time. When the electron attenuation effects are properly included in the XPS data analysis, we obtain excellent agreement with IR measurements for relative values of the DNA coverage, and a calculated absolute coverage value consistent with a previous radiolabeling study. The validation of the analysis procedure for the modelpoly(dT)25 ssDNA film supports its generalization for direct quantitative comparison ofDNA films prepared under widely varying conditions.

Citation

Surface and Interface Analysis

Volume

20

Issue

2

Pub Type

Journals

Keywords

attenuation, composition, coverage, DNA, gold, immobilization, uncertainty, XPS

Citation

Petrovykh, D. , Kimura-Suda, H. , Tarlov, M. and Whitman, L. (2004), Quantitative Characterization of DNA Films by X-ray photoelectron spectroscopy, Surface and Interface Analysis (Accessed October 14, 2024)